Shading of the mother plant during seed development promotes subsequent seed germination in soybean

Abstract

The effect of shading during seed development on subsequent germination remains largely unknown. In this study, two soybean (Glycine max) seed production systems, monocropping (MC) and maize–soybean intercropping (IC), were employed to examine the effects of shading of the mother plant on subsequent seed germination. Compared to the MC soybean seeds, which received light, the developing IC seeds were exposed to shade resulting from the taller neighboring maize plants. The IC seeds germinated faster than the MC seeds, although there was no significant difference in the thickness of the seed coat. The concentration of soluble pro-anthocyanidin in the IC seed coat was significantly lower than that in the MC seed coat. Changes in the concentrations of several types of fatty acids in IC seeds were also observed, the nature of which were consistent with the effect on germination. The expression levels of genes involved in abscisic acid (ABA) biosynthesis were down-regulated in IC seeds, while the transcription levels of the genes related to gibberellin (GA) biosynthesis were up-regulated. This was consistently reflected in decreased ABA concentrations and increased active GA4 concentrations in IC seeds, resulting in an increased GA4/ABA ratio. Our results thus indicated that shading of the mother plant during seed development in soybean promoted subsequent germination by mediating the biosynthesis of pro-anthocyanidins, fatty acids, and phytohormones.

The Impact of Fruit Etiolation on Quality of Seeds in Tobacco

“…The effect of environmental factors, in particular temperature, light, and age, on seed germinability/dormancy is well documented ( Bhatt et al, 2016 ). These effects are also known to be reflected endogenously as changes in phytohormones levels, especially ABA and GA, that finally result in different timing of seed germinability/dormancy ( Chen et al, 2020 ). These properties are in line with what is observed in the present work, where light affects seeds maturity/maturation with a hormone-mediated mechanism.…”

ABA Metabolism and Homeostasis in Seed Dormancy and Germination

“…However, light responses may depend on species and culture conditions. Recently, the effect of light quality has been assessed on seeds harvested from soybean ( Glycine max ) plants grown in the field [ 86 ]. The shading of the mother plant on germination of soybean seeds was analyzed in comparison to that of normal light, in two different field culture conditions, either maize-soybean intercropping or soybean monocropping culture.…”

Identification and Bioinformatic Analysis of the GmDOG1-Like Family in Soybean and Investigation of Their Expression in Response to Gibberellic Acid and Abscisic Acid

“…According to the previous studies, soybean is rich in oil and protein, which leads to the decrease of soybean germination rate, affecting the final yield [3]. Meanwhile, soybean seed germination is deficient, if exposed to diverse environmental stresses, such as salinity, drought or flooding stress, which further results in a serious decrease in final yield [15,16]. The studies of seed germination and dormancy are mainly focused on ABA and GA, and the molecular mechanisms of DOG1 are extensively documented in Arabidopsis [7].…”